Sustainability and the Complexity of Dirty Gym Towels

From Matthew Kahn and the Environmental and Urban Economics blog:

"To reduce its aggregate water consumption, UCLA will soon stop giving towels to users of its gym.  This will not reduce overall water consumption if sweaty people bring their own clean towels that they wash at home. If there are economies of scale in washing towels, then aggregate water used for cleaning up after exercise at UCLA will actually increase.  Why?  Suppose that UCLA can wash 100 towels using 200 gallons of water while each individual can wash her own towel using 5 gallons of water, in this case aggregate water consumption increases from 200 to 1000 gallons when the 100 gym users now go home to wash their towels. UCLA must be implicitly assuming that a large fraction of users of their gym won't bring a towel and will just sun dry after going to the gym.  Is this correct?  The broader point here is that individual entities (such as UCLA or California) calculate their own "sustainability impacts" without considering behavioral responses to their actions. Economic analysis is useful for predicting such behavioral responses.

For some specifics on economies of scale (and resulting water savings) in doing laundry read this.

Rather than banning the towels, UCLA should figure out a collection system (the honor system?) to collect 5 cents per towel with a nudge saying that you are being watched.  This would nudge some folks to choose not to grab a towel and dry off outside."